This invention relates generally to tilt detection, and more particularly concerns the provision of a tilt detector of improved construction and its use in a system for aligning a sub-sea riser pipe with a stack of sub-sea well head equipment.
There is a continuing need for tilt detection equipment characterized by simplicity, rugged construction, insensitivity of low sensitivity to vibration (enabling use on well drilling equipment), two axis tilt sensitivity, immunity to temperature drift, and capability for operation after inversion despite use of liquid mercury as a pendulum. There is also need for a simple control system for maintaining alignment of a riser pipe with sub-sea well head equipment. No prior equipment meets the above needs in the unusually advantageous manner as will be described herein.